Power-driven reciprocating drag saw having two oppositely reciprocating blades



Apnl 29, 1952 H. E. RINGGOLD 2,594,997

POWER-DRIVEN RECIPROCATING DRAG SAW HAVING TWO OPPOSITELY RECIPROCATING BLADES Filed June 16, 1948 2 SHEETS-SHEET 1 49b n/zZZZRz'nggo/d Afforn gy.

2 SHEETS-SHEET 2 HAVING ag-WES H. E. RINGGOLD POWER-DRIVEN RECIPROCATING DRAG TWO OPPOSITELY RECIPROCATING HHHH HIHH M Np MN m n u H n April 29, 1952 Filed June 16, 1948 Patented Apr. 29, 1952 UNITED STATES PATENT o-FFicE 2,594,997 POWER- DRIVEN RECIPROCATING DRAG,

SAW HAVING TWO OPPOSITELY anon-- ROCATING BLADES Homer E. Ringgold, Milford, Del.

Application June 16, 1948,. Serial No. 33,281

-7 Claims. l The object of the invention is to provide immovements in saws, but more specifically in the type'of saw that is used in lumbering operations, and involves the felling of big trees.

Another object 'is to provide a double-blade saw, the blades of which are secured together in such manner as to permit relative reciprocation between them longitudinally, and each blade being provided with a plurality of cutting units, each unit comprising. a plurality of teeth, and each unit being angularly oscillatable about the axis'of apivot by which it is'mounted for limited angular movement upon and in the plane of one of said blades, with means to move the blades simultaneously in opposite directions.

A further object is to provide the respective blades of such a saw with opposed grooves which together form a channel for the reception of sawdust from said toothed cutting. units. said grooves opening through one end or said blades for the discharge of sawdust therefrom beyond the longitudinal limits of said blades.

,Still'anotherfobject is to provide means in each of said channels to propel sawdust towards and from the open end thereof, said means comprising elongated, ratchet-shaped teeth or lugs having abruptly terminating ends directed in one direction common to both of them.

A still further object is to provide in such a 'saw cutting units of which each comprises an arcuate' arrangement of teeth that progressively increase in radial length from the center towards the opposite ends of each unit, so that the lead tooth of each unit engages the wood at an a'cuteangle as would a chisel, and the oppositely directed, acutely positioned teeth of the cutting units of the two blades upon passing each other closely during the normally opposite movement of said blades, and lift fibers within and from th'e-sawcut, which is as wide as the two blades combined.

With the objects thus briefly stated, the invention comprises further details, construction and operation, which are hereinafter fully brought out in the following specification, when read in conjunction with the accompanying drawings, in which Fig. 1 is a side elevation of a double-bladed saw comprising one embodiment of the invention; Fig. la'is a horizontal section through the center-line of the operating head; Fig. 2 is a fragmentary portion of the same,

showing the interior of the operating head and a portion only or the two bladesr Filg. 3 is an enlargedsection on the line 3- -3 of Fig. 1- Fig. 3% is a similarly enlarged demeanor the-inner 2 surface of one of said blades with its seriesof cutting units mounted thereon,'and inthe positions that they occupy when the blade is travelling in the direction of the arrow; Fig. 5 is an inverted enlarged elevation of the inner surface of the other of said blades with its series of cutting units in the positions they occupy when travelling in the direction of the adjacent arrow, the directions of movement is being noted being in opposite directions; Fig. 6 is a plan view of one of the cutting units per se; Fig. 7 is an inner surface elevation of one of the blades of a modified form of the invention; Fig. 8 is a similar view of the other blade of this modification.

Referring to Figs. 1 to' 6 of the drawings, the improved saw comprises essentially a pairof frame members I and 2', the former being provided with a so-called tongue 3 of T-shaped cross section, while the latter is provided with a groove 4 of similar shape, said tongue and groove extending substantially the entire length of the respective blades. Said blades are also provided with oppositely positioned, parallel sawdustreceiving grooves 5 and 6 of rectangular or other suitable cross. section, and with a plurality'of elongated ratchet-toothlike teeth I and 8 that have their abruptly terminating ends directed towards the outer free end of the composite saw, that is, away from the operating head 9 shown in Figs. 1 and 2, and toward the left end of each member when viewed as; in Figs. 4 and 5. In the normal operation of the device, the abraded wood particles enter the grooves 56 in such quantities above each cutting unit, as the frame members rapidly reciprocate, that said grooves would soon become jammed "were it not for the fact that the toothlike means 'l8, by facingfih one direction and reciprocating with their respective supporting members, tend to propel the wood particles towards the forward end a'nd'away fromzthe operating head of the device, andthereby remove the loosewood from the sawcut.

Each of the sawdust-receiving grooves is bounded upon the side away from their respectively adjacent tongue or groove with a raised beading l0, which grooves are interrupted or cut away from ai -portion of their lengths to provide spaces II inwhich are oscillatably mounted the improved form of cutting units l2. Betweensaid cutting units. integral lugs 13 extend inwardly from each of said blades and act as spacing means to prevent binding of the cutting units ofthe: two blades as they pass each. other. In 'thi's.*way. suflicieiit space is providedf fojr' each cutting in. which. it free to oscillatev tram clusive. Each unit comprises a body portion N that is flat and uninterrupted by any surface irregularities upon one side, while its opposite i side is recessed or thinned at H") throughout that angular portion of it that extends between the saw blades, the first-mentioned fiat sidesfof. a

pair of said units being in slidablecontactas the V respective blades which carry them reciprocate in opposite directions, as indicated in :Fig. 3. From the wall of the recess l there arises centrally either an integral or a separable pin l6, that extends slidably. into one of the apertures I! in one of the saw blades l and 2, and-which pin forms a pivot mounting for oscillatably securing the unit in operative position, the degree of oscillation of theunit being limited by cooperation of one or the other end of af'sh'oulder I8, .that comprises a wall of said recess-l5 and which abuts against the normally under edge or surface IQ of the supporting blade.

. When viewed as operatively assembled within and as a unitarypart of the composite saw, that portion of the cutting unit that. projects from between the blades comprises aseries-of teeth 3| by said operating head. However, it must be understood that the means of operation here shown is purely illustrative and is not intended in any way to limit the scope of the invention, that primarily resides in the construction and inter-relationship of the two blades and the plu- :ralityvof cutting units carried by them, the saw- -dust receiving channel and the impelling means within said channel.

'In considering the present invention, it is to be also understood that it is not limited to the shape of the sawdust-propelling, ratchetlike teeth 1 and 8, but only to the operative relationship of these several parts, and the general con- I9 and 20. The central teeth l9 are of substantially conventional shape, while the. oppositely positioned teeth 20 are much more acute, and instead of their leading edges dragging over the inner surface of the sawcut as'is, customarily the case, they function more as chisels and each of them undercuts the wood of one half the width of the sawcut at the bOttQlllOf the cut, thus raising it somewhat as a chisel or plane raises its shaving. In this 'way one suchjunit tooth cuts its half shaving away from one wall of the sawcut and after deflecting it upwardly from the bottom thereof into the complementarygrooves 5-6, a blade of a passing unit cuts the other half of the shaving from the bottom of its side of the out, and the wood thus cut is also deflected upwardly as so-called sawdust and passes between the cutting units and into the complementary registering grooves '5B, where it is forced by subsequently intermittently added quantities towards one or the other end thereof by the reciprocating ratchetlike teeth 1 and 8, and is pushed by succeeding wood particles and in time discharged from the free end 0f the combined blades. e

For relative reciprocation of the said blades any suitable mechanism may be employed. In

'the'embodiment here illustrated said blades are detachably-secured to supporting elements 2|, which extend slidably into an enlarged hollow operating head 9. Each of said elements is connected by means of a pivoted link 22 to one of a pair of bevel gears 23, which rotate in opposite directions as driven by an intervening bevel pinion 24. This pinion is driven by a shaft 25, that connects through a fiexiblecoupling 26 with any suitable source of power (not shown), said shafts being operatively connected at will by means of a clutch 21, thatjishere shown conventionally as being actuated by a lever'28, that is connected through'an intervening link '29 with I a. manually actuable-lever '80 pivotally'carried at struction, functioning and operation of the composite whole. f

Referring to Figs. 7 and 8, short lengths of a simplified form of the invention is shown as comprising a pair of 'blades 32 and 33,-one of which is provided with a groove 34 of substantially T-shaped cross section, while the other is provided with'a tongue 35 of similar cross section, said tongue and groove preferably extending substantially the entire length of the respective blades and being closely slidable with respect to each other. In this instance the cutting elements are not oscillat'ably carried by the respective blades, but comprise shortened toothed sections 35 detachably carried by said blades. .The teeth of these sections are in general of the more conventional type and may be said to drag upon and thereby abrade the wood of the sawcut, as distinguished from undercutting the same as a chisel, and as hereinbefore'described with respect to the preferred form of the invention. As in the embodiment hereinbefore first described, the two modified blades maybe relatively reciprocated by any suitable-driving mechanism, as for example the operating head 9 above described.

Having thus described my invention, what I claim and desire to protect by Letter Patent of the United Statesis:

l. A saw, comprising a pair of relatively reciprocatory members secured together in slidable .engagement and forming between them a longitudinal channel open at one end and along one side, means to reciprocate said members alternately in opposite directions, toothed elements pivotally carried by said members within said channel and protruding through the open side thereof, each of said-elements comprising a series of teeth,-those teeth at the opposite ends of said seriesalternately engaging the bottom of asawcut at an acute angle, while-the intervening teeth in engagement with the bottom ofthe sawcutoperate to angularly oscillate the element at each change in direction of the member carrying I it, means to limit the angular movement of said 2. Asaw, comprising a pair of relatively reciprocatory members each of said members having a side face, one of said members further having a longitudinally extending cut-away portion opening .at'one side and at one longitudinal edge 1.1; of. said member, means slidably securing said members together with said; faces abutting each l'o'ther. and the other of said members overlying said cut-away portion, whereby said members together define a single longitudinally extending recess opening in one direction, the longitudinal edge surfaces of said members at the mouth of said channel providing a pair of spaced bearing surfaces, power means to actuate said members simultaneously in opposite directions, and toothed elements pivotally carried by each of said members in said recess and operative to assume opposite angular positions as the direction of movement of said members changes, each of said elements comprising a laterally outward- 1y directed shoulder that overhangs and is en gageable with the bearing surface of its supporting member, to limit the oscillatory movement of said elements in opposite directions.

3. A saw, comprising a of relatively reciprocatory members each of said members having a side face, one of said members further having a longitudinally extending cut-away portion opening at one side and at one longitudinal edge of said member, means slidably securing said members together with said faces abutting each other, and the other of said members overlying said cut-away portion, whereby said members together define a single longitudinally extending recess opening in one direction, the longitudinal edge surfaces of said members at the mouth of said channel providing a pair of spaced bearing surfaces, power means to actuate said members simultaneously in opposite directions, toothed elements pivotally carried by said members within and protruding from said recess, and operative to assume opposite angular positions as the direction of movement of said members changes, and a shoulder carried by each element that overhangs and is engageable with the bearing surface of its supporting member laterally of said recess, to limit the angular movement of said elements, said elements passing closely by one another within and extending freely from said recess to combine in producing a single sawcut.

4. A saw, comprising a pair of reciprocatory members, means to slidably secure said members together, power means to actuate said members simultaneously in opposite directions, a sawdustreceiving channel between said members and open at one end, toothed elements pivotally carried by each of said members within and extending freely from said channel and operative to assume opposite angular positions as the direction of movement of said members changes and to direct sawdust into said channel, means to limit the angular movement of said elements, and ratchet-toothlike means carried by said members in said channel to propel sawdust towards and from said one end of said members as said members rapidly reciprocate.

5. A saw, comprising a pair of reciprocatory members, means to slidably secure said members together, power means to actuate said members 6 simultaneously in opposite directions, a sawdustr ceiving channel between said members and open at one end, toothed elements pivotally carried by each of said members within and extending freely from said channel and operative to assume opposite angular positions as the direction of movement of said members changes and to direct sawdust into said channel, and means to limit the angular movement of said elements, elements passing closely by one another to ombine in producing a single sawcut, and *atchet-toothlike means carried by said members '51 said channel and reciprocatable with said nembers to propel sawdust into and from said one end of said channel.

6. saw, comprising a pair of relatively reciprocatory members, a tongue-and-groove joint between and securing said members together in slidable cooperation, a longitudinally extending channel between said members open along one side to receive sawdust and open at one end to discharge sawdust therefrom, a power head into which one end of each of said members extends, means within said head to reciprocate said memsimultaneously in opposite directions, toothed elements pivotally carried by said members within said channel and protruding through the open side thereof, and ratchet-toothlike means in said channel to propel sawdust towards said discharge end, and means to limit the angunovement of said elements in relatively opposite directions.

7. A saw, comprising a pair of relatively reciprocatory members, a tongue-and-groove joint 5 between and securing said members together in slidable cooperation, and forming between them a longitudinal channel open at one end and along one side, a power head into which one end of each of said members extends, means within said head to reciprocate said members simultaneously in opposite directions, toothed elements pivotally carried by said members within said channel and protruding from between said members through the open side of said channel, and ratchet-toothlike means in said channel reciprocatable with said members to propel sawdust within and towards the open end of said channel.

HOMER E. RINGGOLD.

CES CKTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 108,425 Young Oct. 18, 1870 139,426 Scholfield May 27, 1873 1,414,265 Dylnicki Apr. 25, 1922 1,537,980 Asselin May 19, 1925 1,726,863 Singer Sept. 3, 1929 2,085,756 Joy July 6, 1937 

